Metal doors often get dinged and dented from small accidents. It is possible to remove such dents without using a plunger or drilling into the metal door. This method can be used for a variety of dents and metal doors including car door panels, metal basement doors and even stove and stainless steel refrigerator doors. It uses only a heat source like a hair dryer and compressed air.
Assess the entire area of the dent in your metal door. Take note of how deep and how far the dent extends on the car door or refrigerator panel. Then, thoroughly clean the dented area with water and a towel to remove grease, dirt and sand.
Heat the metal door dent with the hair dryer, or heat gun holding it a few inches from the metal panel and moving it slowly across the entire area of the dented door. The object is to heat up the entire damaged area. If you are using a heat gun, be careful not to place it too close to the metal door panel, as it may get hot enough to burn the paint or melt the wax off the surface.
Place the heat gun down on a safe surface like a cement floor. Then hold the can of compressed air upside down in front of the dent in the metal door. The spray nozzle must face the dented metal door. Depress the trigger and spray the compressed air over the damage, covering the entire dent. Only the colder CO2 gas should escape and land on the door.
Wait several seconds while the metal quickly contracts. This action will reshape the dent causing it to pop out on its own. If this does not happen, reheat the area longer and spray more compressed air on the dent.